Bi-directional transceiver with time synchronization

Abstract

An optoelectronic module may include an optical receiver optically coupled with an optical fiber. The optical receiver may be configured to receive time synchronization signals from the optical fiber. The time synchronization signals may be frequency modulated, wavelength modulated, or amplitude modulated and may be received along with received data signals. A time synchronization signal detection module may be communicatively coupled to the optical receiver. The time synchronization signal detection module may be configured to receive the time synchronization signals that are transmitted through the optical fiber and detect frequency modulations, wavelength modulations, or amplitude modulations to recover the time synchronization signals.

What is claimed is: 
     
       1. An optoelectronic module comprising:
 an optical receiver optically coupled with an optical fiber, the optical receiver configured to receive time synchronization signals from the optical fiber, wherein the time synchronization signals are amplitude modulated and are received along with received data signals; and 
 a time synchronization signal detection module communicatively coupled to the optical receiver, the time synchronization signal detection module configured to receive the time synchronization signals that are transmitted through the optical fiber and detect amplitude modulations to recover the time synchronization signals, the time synchronization signal detection module comprising:
 an amplifier; 
 a low pass filter, wherein the input of the filter is coupled to the output of the amplifier; and 
 a limiting amplifier, wherein the sole input of the limiting amplifier is coupled to an output of the low pass filter. 
 
 
     
     
       2. The optoelectronic module of  claim 1 , wherein the amplifier receives the time synchronization signal from the optical receiver and amplifies the signals, the low pass filter filters out the time synchronization signals, and the limiting amplifier allows the time synchronization signals below a specified input level to pass through it and attenuates peaks of the time synchronization that exceed the specified input level. 
     
     
       3. The optoelectronic module of  claim 1 , further comprising:
 a receiver power monitor coupled to the optical receiver; and 
 a transimpedance amplifier coupled to the optical receiver, the transimpedance amplifier configured to process or modulate data signals received by the optical receiver. 
 
     
     
       4. The optoelectronic module of  claim 1 , further comprising:
 an optical transmitter optically coupled with the optical fiber; and 
 a controller communicatively coupled to the optical transmitter, the controller configured to operate the optical transmitter to transmit data signals through the optical fiber. 
 
     
     
       5. A system comprising:
 the optoelectronic module of  claim 1 ; and 
 an optical multiplexer or demultiplexer optically coupled between the optoelectronic module and the optical fiber. 
 
     
     
       6. The system of  claim 5 , wherein the optical fiber is a bidirectional optical fiber. 
     
     
       7. The system of  claim 5 , wherein the system is a bidirectional dense wavelength division multiplexing system or a bidirectional colorless system, and the system is configured to transmit data signals and time synchronization signals in a first direction and an opposite second direction through the optical fiber. 
     
     
       8. An optoelectronic module comprising:
 an optical receiver optically coupled with an optical fiber, the optical receiver configured to receive time synchronization signals from the optical fiber, wherein the time synchronization signals are amplitude modulated and are received along with received data signals; and 
 a time synchronization signal detection module comprising:
 an amplifier; 
 a low pass filter coupled to the amplifier; and 
 a limiting amplifier coupled to the low pass filter, wherein the limiting amplifier allows the time synchronization signals below a specified input level to pass through it and attenuates peaks of the time synchronization that exceed the specified input level. 
 
 
     
     
       9. The optoelectronic module of  claim 8 , wherein time synchronization signal detection module receives the amplitude modulated time synchronization signals that are transmitted through the optical fiber and detects amplitude modulations to recover the time synchronization signals. 
     
     
       10. The optoelectronic module of  claim 8 , wherein the amplifier receives the time synchronization signal from the optical receiver and amplifies the signals. 
     
     
       11. The optoelectronic module of  claim 10 , wherein the low pass filter filters out the time synchronization signals. 
     
     
       12. The optoelectronic module of  claim 8 , further comprising:
 a receiver power monitor coupled to the optical receiver; and 
 a transimpedance amplifier coupled to the optical receiver, the transimpedance amplifier configured to process or modulate data signals received by the optical receiver. 
 
     
     
       13. The optoelectronic module of  claim 8 , further comprising:
 an optical transmitter optically coupled with the optical fiber; and 
 a controller communicatively coupled to the optical transmitter, the controller configured to operate the optical transmitter to transmit data signals through the optical fiber. 
 
     
     
       14. A system comprising:
 the optoelectronic module of  claim 8 ; and 
 an optical multiplexer or demultiplexer optically coupled between the optoelectronic module and the optical fiber. 
 
     
     
       15. The system of  claim 14 , wherein the optical fiber is a bidirectional optical fiber. 
     
     
       16. The system of  claim 14 , wherein the system is a bidirectional dense wavelength division multiplexing system or a bidirectional colorless system. 
     
     
       17. The system of  claim 14 , wherein the system is configured to transmit data signals and time synchronization signals in a first direction and an opposite second direction through the optical fiber.